Mycoplasma. This disease is so common, it’s hard to find rats that are free from it. The most common symptoms are sneezing and wheezing, but if the infection is far enough along, it can also cause gasping for breath. Mycoplasma, or, mycoplasmosis, is a respiratory infection that is extremely contagious (from rat to rat, not from rat to human), and it is incurable. It can be spread by direct contact, through the air, and from your touching an infected rat and then touching a healthy rat. The symptoms can be increased by cigarette smoke, ammonia from dirty cages, and vitamin A or E deficiency. Mycoplasma causes a blister effect on the surface of the lungs. It can also cause lung abscesses, emphysema, and infection of the uterus. Rats that have the disease usually act quite normal, besides the sneezing, and will eat well and be otherwise healthy, until the disease is quite advanced. For more in-depth information on treating and scientific facts, please see the links page under “Health Problems.”